D-Link DIR-823X Command Injection Vulnerability
D-Link DIR-823X contains a command injection vulnerability that allows an authorized attacker to execute arbitrary commands on remote devices by sending a POST request to /goform/set_prohibiting via the corresponding function. The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization.
Quick answer
D-Link DIR-823X should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- 240126
- 240802
- -
Fixed versions
- Apply the latest vendor-supported patched version.
How to fix it
CVE-2025-29635 affects D-Link DIR-823X devices and the vendor advisory identifies the product as end-of-life and end-of-service. Because supported firmware development has ended, the reliable fix is to retire and replace the router rather than depend on a future patch. If immediate replacement is not possible, reduce exposure while planning replacement by disabling remote administration, using the newest available firmware, and isolating the device.
- Identify all D-Link DIR-823X devices, hardware revisions, firmware versions, and whether any management interface is exposed to WAN or untrusted networks.
- Schedule replacement with a supported router or firewall platform; treat continued DIR-823X use as residual risk.
- Until replacement is complete, install the latest firmware available for the exact region and hardware revision if one exists.
- Disable WAN-side administration, UPnP, unnecessary port forwarding, cloud management, and any unused services.
- Set a unique strong administrator password and rotate Wi-Fi credentials where the device may have been exposed.
- Place the device behind a trusted upstream firewall or isolate it from sensitive internal networks.
- Monitor for unexpected DNS changes, port forwards, new users, configuration changes, or outbound traffic spikes.
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Verify the fix
- Confirm the affected DIR-823X device has been replaced, or document the accepted temporary risk and mitigation owner.
- Verify remote administration and unnecessary services are disabled from the WAN side.
- Scan from an external network and confirm no management interface is publicly reachable.
- Review configuration backups for unauthorized changes before and after mitigation.
- Run a Fixnx scan against public assets behind the router after replacement or isolation.
Related categories
Trusted references
FAQ
What is affected by CVE-2025-29635?
D-Link DIR-823X should be checked against the vendor advisory and trusted references linked on this page.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
Why can this risk appear in multiple categories?
A vulnerability can belong to more than one platform or ecosystem. Fixnx keeps one canonical risk page while also listing it in every relevant category.